Cushing's disease: Clinical manifestations and diagnostic evaluation

The most common endogenous cause of rushing's syndrome is Gushing's disease . Frequent clinical findings include weight gain, truncal obesity, striae, hypertension, glucose intolerance and infections. Cranial nerve II may be a ffected by enlarging pituitary adenomas in Gushing's disease; cranial nerve s Iii, IV and VI may also be affected. The evaluation of patients with susp ected Gushing's disease and syndrome requires an understanding of the prope r use and limitations of the tests commonly included in the diagnostic work -up. The best screening test for Gushing's syndrome is a 24-hour urine coll ection with analysis for urinary free cortisol excretion. Low-dose and high -dose dexamethasone suppression tests, corticotropin assays, a corticotropi n-releasing hormone stimulation test and inferior petrosal sinus catheteriz ation may be required for a definitive diagnosis. Magnetic resonance imagin g is useful in localizing the lesion. Surgical removal of the lesion by a t ransphenoidal approach is usually successful, but long-term follow-up is re quired. Some patients require,lifetime glucocorticoid replacement therapy.